Graphic recorder apparatus having means for printing an elapsed time code on the recording



3,454,953 N'I'ING July 8, 1969 w. A. LLOYD ET AL GRAPHIC RECORDER APPARATUS HAVING MEANS FOR PRI AN ELAPSED TIME CODE ON THE RECORDING Filed Aug. 21, 1967 INVENTORS WILLIAM A. LLOYD RICHARD GSWEET A ORNEY United States Patent 3,454,953 GRAPHIC RECORDER APPARATUS HAVING- MEANS FOR PRINTING AN ELAPSED TIME CODE 0N THE RECORDING William A. Lloyd, San Jose, and Richard G. Sweet, Palo Alto, Calif., assignors to Varian Associates, 'Ialo Alto, Calif., a corporation of California Filed Aug. 21, 1967, Ser. No. 661,868 Int. Cl. Gtlld 15/08 U.S. Cl. 34623 2 Claims ABSTRACT OF THE DISCLOSURE A graphic recorder apparatus is disclosed which includes means for printing an elapsed time code on the recording. The recording medium such as a strip chart includes a plurality of narrow timing zones printed thereon and extending lengthwise of the recording strip. Respective ones of the timing zones are marked to represent a certain predetermined time interval such as 0.1 second, 1 second, 10 seconds, 1 minute and 10 minutes, respectively. A timing pulse generator generates several trains of timing pulses with the pulse spacing corresponding to the predetermined time intervals indicated in the time zones on the recording strip. A timing selector switch is provided which selects the train of pulses having the smallest time interval of time marks to be recorded on the recording strip. The selector switch also serves to interconnect a timing mark writing means disposed in registration with the selected minimum time interval zone for producing a series of timing code marks in the appropriate timing zone on the recording medium. In addition, the selector switch also interconnects the other trains of timing pulses, having longer time intervals than the minimum selected, to their respective marking means in registration with their respective timing zones for marking same.

In a preferred embodiment, the minimum selected time interval between pulses of the pulse train produces the timing grid lines on the recording strip chart such that the time interval between the grid lines is readily established by noting the time zone having the timing marks therein which are in alignment with the timing grid lines on the recording strip. Elapsed time between recorded events is readily ascertainable by adding certain readings derived from the respective time zones.

Description of the prior art Heretofore, it has been proposed to lay down a sequence of timing grid lines across a strip chart of an electrographic recorder. Such a recorder apparatus is described and claimed in copending U.S. application 578,801 filed Sept. 12, 1966, now Patent No. 3,392,401, and assigned to the same assignee as the present invention. A problem with such an arrangement is that, although the spacing between successive timing grid lines is precisely determined regardless of the chart speed, there is no way to identify the time interval between adjacent grid lines in the absence of the operator making some notation on the chart as to the time interval of timing grid lines. In addition, it is relatively diflicult to ascertain from the recording the elapsed time between two recorded events since each of the grid lines would have to be counted to arrive at a summation of the elapsed time between the recorded events.

Therefore, it is desirable to provide means for coding the timing grid lines on the recording chart such that the time interval between successive grid lines is readily ascertained from the chart. In addition, it is desirable to provide means for printing coded time marks corresponding 3,454,953 Patented July 8, 1969 to various increasing intervals of time to facilitate count- Summary of the present invention The principal object of the present invention is the provision of an improved graphic recorder apparatus.

One feature of the present invention is the provision, in a graphic recorder apparatus, of means for printing concurrently a first and a second sequence of timing indicia on a strip recording, the first sequence of timing indicia corresponding to a first predetermined interval of time between successive indicia and the second sequence of timing indicia having a spacing representative of a summation of the elapsed time represented by a predetermined number of the first timing indicia, whereby totaling of the elapsed time between two recorded events is facilitated.

Another feature of the present invention is the same as the preceding feature wherein the recording chart includes a plurality of predetermined timing zones defined thereon and extending lengthwise of the recording chart and wherein the first sequence of timing indicia are printed in the first timing zone and the second sequence of timing indicia are printed in the second timing zone.

Another feature of the present invention is the same as any one or more of the preceding features wherein the graphic recorder is an electrographic recorder having an array of signal and time indicia writing electrodes disposed adjacent the surface of the recording medium.

Another feature of the present invention is the same as the preceding feature wherein the recorder includes a timing pulse generator generating a concurrent series of pulse trains having a different predetermined pulse interval and a timing selector switch for applying certain selected ones of the pulse trains to appropriate timing mark electrodes for printing the timing indicia on the recording medium in the appropriate timing zone defined thereon.

Other features and advantages of the present invention will become apparent upon a perusal of the following specification taken in connection with the accompanying drawings wherein:

Brief description of the drawings FIG. 1 is a schematic perspective diagram, partly in block diagram form, of an electrographic recorder in corporating features of the present invention, and

FIG. 2 is an enlarged detail circuit diagram of the portion of FIG. 1 delineated by line 22.

Description of the preferred embodiments Referring now to FIG. 1, there is shown an electrographic recorder 1 incorporating features of the present invention. The recorder 1 includes an analog input signal channel 2 having a pair of input terminals 3 and 4 to which an analog input signal E is applied to be recorded. The input signal is fed to an analog-to-digital converter 5 which converts same to a binary data output 6 which is representative of the amplitude of the input signal E to be recorded. The binary data output 6 is fed to an array of signal tracing electrodes 7 arranged in a linear array extending crosswise of an electrographic recording web 8. The recording web 8 has preprinted thereon an amplitude scale 9. The signal tracing array 7 is disposed in registration with the amplitude scale 9 such that certain ones of the writing electrodes 7 correspond to certain amplitudes of the signal to be recorded. The binary data output 6 from the analog-to-digital converter 5 selectively energizes the appropriate writing electrode 7 for recording the amplitude of the input signal E and producing the trace 11 of the input signal on the recording web 8.

The recording web 8 includes a conductive paper backing with a dielectric charge retentive film. formed on the surface of the paper. The recording web 8 is disposed with the charge retentive film adjacent the writing electrodes 7. A second writing electrode 12, in the form of a plate, is disposed on the conductive paper side of the recording web 8 and opposite the writing electrodes 7. A suitable high negative potential, more fully described below, is applied to the writing electrodes 7, as of minus 500 to 600 volts relative to the electrode plate 12, for depositing a charge image on the recording web 8 to be developed.

The recorder 1 includes a plurality of event marker input channels 14. The recording web 8 is printed with a plurality of narrow event recording zones 15, as of 1-5, extending lengthwise of the recording web 8. An array of event marking electrode structures 16 are disposed adjacent the recording web 8 with one event marker electrode 16 disposed in registration with each of the event zones on the recording web. Input event signals applied to the various event marker input channels 14 selectively energize the event writing electrodes 16 to produce event marks 17 on the recording web 8. A manually operated event switch 18 in one of the event channels 14 permits the operator to make event marks 17.

The recording web 8 is pulled from a supply roll 21 past the array of writing electrodes 7 and 16 by means of a motor driven friction drive, not shown. The speed at which the paper is pulled from the supply roll 21 is variable over a relatively wide range as of from 1 inch per hour to 100 inches per second. A timing indicia writing electrode structure 22 is disposed extending crosswise of the recording web 8 and is closely spaced to the two signal writing electrode arrays 7 and 16, respectively.

The timing electrode structure 22 includes an elongated electrode portion 23 (-bar) extending crosswise of the recording web 8 and arranged to print an array of parallel thin transverse grid lines 24 at certain predetermined time intervals, as of 0.1 second, 1 second, 10 seconds, 1 minute, or 10 minutes, depending upon the setting of a selector switch 25 disposed on the front panel of the recorder for use by the operator of the recorder. The timing electrode structure 22 also includes a second electrode portion formed by an array of electrodes 26 disposed in transverse alignment with the timing bar electrode portion 23 and arranged with one of the electrodes disposed in alignment with each one of a plurality of narrow timing zones 27 printed on the recording web 8 and extending lengthwise of the web 8.

The timing zones 27 are each preprinted with different time intervals corresponding to selectable time intervals between successive timing pulses applied to the timing electrode structure 23, more fully described below. For example, the various timing zones 27 may be preprinted with timing intervals such as 0.1 second, 1 second, 10 seconds, 1 minute and 10 minutes, as shown.

A pulse generator, generally designated by the dotted box 31, concurrently generates several pulse trains having pulse intervals corresponding to the predetermined timing intervals designated in the timing zones 27. For example, one train of pulses is generated having a timing interval of 0.1 second, a second train is generated having a pulse interval of 1 second and so on and so forth. The pulse generator 31 includes a pulse shaper 32 which is connected into the 60 cycle line current via plug 33. The pulse shaper detects the zero amplitude crossings of the 60 cycle input signal to derive a sequence of pulses having a repetition rate of 120 pulses per second and having a pulse length of 1 millisecond. The output of the pulse shaper 32 is fed to a counter circuit 34 which counts the input pulses to derive a plurality of concurrent outputs 35. The outputs 35 include separate trains of pulses, as previously described forming the output of the pulse generator 31.

The separate pulse train outputs 35 from the pulse generator 31 are connected to contacts 36 and 37 of the dual deck timing selector switch 25. More specifically, each of the contacts 36 in the upper deck of the switch 25 are connected to a separate one of the outputs of the pulse generator 31. Likewise, each one of the contacts 37 on the second deck on the selector switch 25 is connected to an output pulse train of the pulse generator 31.

The wiper blade 38, in the first deck of the selector switch 25, is connected to the timing grid line marking electrode 23 such that when the selector switch 25 is switched from one position to another position the timing interval is changed for the timing grid lines 24 on the recording web 8. The wiper blade 39 for the second deck of the selector switch 25 includes an arcuate blade portion for grounding out a selected number of the pulse train outputs of the counter 34 as fed to the array of time marking writing electrodes 26.

When the timing selector switch 25 is in the OE position, as shown in the drawing, the wiper blade 39 on the second deck of the switch shorts all of the outputs of the pulse generator 31 to ground such that none of the outputs of the second deck of the selector switch 25 which are fed to the writing electrodes 26 is of sufficient amplitude to energize any of the electrodes 26. Therefore, when the selector switch 25 is in the off position no timing marks are printed in the timing zones 27.

When the selector switch 25 is switched to the second position indicated as 10M (10 minutes), the timing interval between successive timing pulses applied to the timing bar 23 is then 10 minutes and the arcuate wiper blade 39 shorts out all of the contacts 37 with the exception of the 10 minute contact which supplies the 10 minute pulses to the appropriate timing zone writing electrode via lead 41 for making timing marks in the 10 minute zone.

When the selector switch 25 is switched over to the shortest time interval, namely, the 0.1 second timing interval, the 0.1 second interval train of timing pulses is applied to the timing grid writing electrode 23 and the shorting wiper blade 39, on the second deck of the switch 25, is moved to a position such that it does not short out any of the outputs of the contacts 37. Thus, all of the output trains of timing pulses are applied to their respective zone writing electrodes 26.

The timing marks in the timing zones 27 form a code which readily facilitates measurement of elapsed time occurring between two events recorded on the recording web 8. More specifically, the time interval between succcessive timing grid lines 24 is readily ascertained by noting in which time zone the timing marks occur which are opposite successive time grid lines 24. In the case illustrated in the drawing of FIG. 1, the grid lines 24 are 1 second apart since the timing mark indicators, in registration with successive grid lines 24, occur in the 1 second time zone.

Measurement of elapsed time between relatively widely separated events in time are easily measured from the coded information within the time zones 27 by first counting the number of timing marks in the longest interval time zone occurring between the two events on the recorded chart 9. More specifically, the operator would look to the longest interval time zone, which in the case illustrated is 10 minutes, and he would count the number of 10 minute intervals falling with the 10 minute zone in the region intermediate the length of the chart between the two events to be measured. The operator would then add to this amount of time the number of 1 minute timing intervals occurring between the first 10 minute interval and the first event and the last 10 minute interval and the last event. The operator would then add to the minute information the number of 10 second intervals existing between the first and the last 1 minute timing marks and the events. To this value the operator would add the number of 1 second timing marks between the first and last 10 second timing marks and the events. To this time the operator would add the number of 0.1 second timing marks between the first and last 1 second marks and the events to be measured. A summation of the timing marks as above indicated will yield the time between the two events to A of a second without the necessity of counting each of the second timing lines on the recording.

Since the output signals of the analog-to-digital converter, event signals and the output pulses of the pulse generator 31 are generally on the order of a few volts, these relatively low voltages are employed to switch the relatively high writing potentials applied to the writing electrodes by means of transistor gates 43 provided in series with each of the writing electrodes.

Referring now to FIG. 2 the gate circuit is more clearly shown. Relatively high voltage bus 44 is energized with relatively high positive voltage as of plus 300 volts. The bus 44 is connected to the writing electrode 7, 26, or 16 via the intermediary of a relatively high series resistor 44. A gating transistor 46 is connected between the series resistor 45 and ground. The base electrode 47 of the transistor 46 serves to receive the writing control signal. The transistor 46 is biased such that the transistor is typically in the otf position such that the potential applied to the bus 44 is applied to the writing electrode 7, 26 and 16 such that no output signal is recorded on the electrographic recording Web 8 due to the insuflicient voltage drop between the plus 30 volts and the plus 600 volts on the second writing, electrode 12. However, when the writing electrode is selected for writing, the control low voltage signal applied to the base 47 causes the gating transistor 46 to become conductive, thereby dropping the potential on the writing electrode 7, 26 or 16 to ground potential to produce a. minus 600 volts on the writing electrode relative to the plate electrode 12 and causing a charge image to be deposited on the recording web 8.

The various charge images deposited upon the recording web 8 are developed by pulling the web underneath an inking channel 48 having an inking slot 49 in the side thereof adjacent the web 8. An electrographic toner (ink) is caused to be passed through the inking channel 48 such that the toner comes in contact with the charge images to be developed on the recording web 8. Charged inking particles are drawn out of the inking channel and deposited on the web to produce the inked or developed images on the web 8. In a preferred embodiment, the electrographic toner is a quick drying liquid having colloidally suspended inking particles therein. The colloidally suspended particles are drawn from the liquid vehicle to the charge image or development.

Although the present invention has been described as employing an electrographic recording web 8 having preprinted timing zones 27 and event channels 15 this is not a requirement. In a preferred embodiment, not shown, a scale printing roller electrode would lay down a charge image pattern on the recording web 8 for subsequent development by the inking channel 48 such that unprinted electrographic recording paper 8 may be employed. An electrographic recorder employing such a chart printing electrode structure is described and claimed in the aforecited copending U.S. application 578,801.

Since many changes could be made in the above construction and apparently widely different embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. In an electrographic recorder apparatus, means forming an array of signal trace writing electrodes, such array extending in a direction crosswise of a signal recording zone of an electrographic recording medium, said array of electrodes being disposed adjacent the surface of the recording medium, said array of electrodes being responsive to a signal to be recorded for producing a signal trace on the recording medium, the recording medium having a plurality of predetermined timing zones defined thereon and extending lengthwise of the recording medium. The improvement comprising, a timing electrode structure having first and second portions for printing first and second sequences, respectively, of timing indicia in first and second ones, respectively, of said timing zones, said first sequence of timing indicia providing an indication of the elapsed time on the recording medium, and said second sequence of timing indicia being representative of the lapsed time represented by a predetermined number of the timing indicia of said first sequence, and wherein said timing electrode structure includes an elongated electrode portion extending crosswise of a preponderance of the width of said signal writing zone on the recording medium for printing an array of parallel transverse timing grid lines in said signal writing zone.

2. An apparatus according to claim 1 including means for simultaneously energizing said elongated grid line writing electrode portion and said electrode portion which writes said first sequence of timing indicia in said first timing zone, whereby the indicia in said first timing zone are representative of the timing between successive timing grid lines in said signal recording zone.

References Cited UNITED STATES PATENTS 2,739,865 3/1956 Willey 346-33 3,039,101 6/1962 Perdue 346-23 X RICHARD B. WILKINSON, Primary Examiner. JOSEPH W. HARTARY, Assistant Examiner.

U.S. Cl. X.R. 346-49, 74 

